1. Field
Example embodiments relate to a non-volatile semiconductor memory device and a method of programming the same, and more particularly, to a non-volatile memory device in which program disturb is reduced and a method of programming the same.
2. Description of Related Art
A non-volatile memory device is a memory device in which data is retained even when power is removed. In contrast, in volatile memory devices, e.g., a dynamic random access memory (DRAM) or a synchronous random access memory (SRAM), data is lost when power is removed.
An electrically erasable programmable read-only memory (EEPROM) is a representative non-volatile memory device. The EEPROM is used to store permanent code, is typically programmed in unit of bytes, and is erased in units of blocks or sectors. Recently, a flash memory which is erased in units of bytes has been suggested, and as a representative example of a flash memory which is erasable in units of bytes, there is an EEPROM of a two transistor Fowler-Nordheim (2T FN) type.
The EEPROM of the 2T FN type refers to an EEPROM in which each memory cell is configured by two transistors, and a programming operation and an erase operation are performed by Fowler-Nordheim (FN) tunneling. The two transistors which configure the memory cell are serially connected. One of the two transistors is a memory transistor of a floating gate tunnel oxide (FLOTOX) type, and the other is a selection transistor.
A non-volatile semiconductor memory device using the EEPROM of the 2T FN type stores data by accumulating electrons on a floating gate by FN tunneling generated when a voltage of a certain condition is applied to a memory transistor selected at the time of a program operation. However, program disturb, in which a memory cell which is not selected at the time of the program operation is simultaneously programmed, may occur. The program disturb should be minimized for a reliable memory device.